I think this is a topic which is often misunderstood by some newer members.

Just like banks buy through banks and then they in turn buy through Euroclear or Clearstream etc. etc. The guy you see buying is rarely the guy buying. Same goes for selling. You may see TD buy 500,000 shares and then sell 100,000 minutes later, but these are just folks/banks purchasing through TD either in one lot or bulk.

When its bulk you haven't a chance in Hades of knowing whose actually buying, you just know who the most popular conduit is. We always had problems with this in my previous job, deciphering who should be paid commission when a deal is for 1 million units, but there are 20 counter-parties claiming to be behind it. To be honest, I wouldn't even try to understand who is and who isn't buying from the share reg.